Swivel base for a chair stool



FIG. 1 is a bottom perspective view of a swivel base of the new design.

FIG. 2 is a top plan view of the swivel base of the new design.

FIG. 3 is a front elevational view of the swivel base of the new design with the rear elevational view being identical thereto; and,

FIG. 4 is a left side elevational view of the swivel base of the new design with the right side elevational view being identical thereto. 

The ornamental design for a swivel base for a chair stool, as shown and described. 